Firearms, such as automatic weapons, have locking systems that include a locking mechanism that advantageously enables the firearm to be locked while a round is being fired and thereafter to be unlocked to facilitate a loading process. Specifically, during the loading process, the locking system utilizes a loading mechanism to reload the firearm to enable the firearm to be refired.
Different known locking systems are available that have different loading mechanisms such as, for example, gas pressure loaders or recoil-operated firearms. Typically, these known loading mechanisms enable the firearm (e.g., an automatic firearm or a semi-automatic firearm) to be automatically loaded or reloaded. However, some known loading mechanisms, may be manually loaded or reloaded. Additionally, some known loading mechanisms may be provided with a feature that enables a marksman to manually load or reload a semi-automatic or automatic firearm or that enables the marksman to manually open or close the locking mechanism of a semi-automatic or automatic firearm.
Generally, firearms provided with a gas pressure loader are self-loading firearms having a locking mechanism with a secured lock. Specifically, after a shot is fired through these firearms, a portion of the propellant gas is rerouted through a pipe to release and open the lock of the locking mechanism to initiate the reloading process.
In operation, the lock of a gas pressure loader is not deactivated until a bullet has passed a designated point in the barrel. The amount of propellant gas rerouted to the loading mechanism may be controlled by a valve to change a cadence of the firearm or to enable different types of munitions or munition assemblies to be utilized.
In some examples, the portion of the gas propellant is directed through a gas discharge and toward a gas piston. The gas propellant acts against the gas piston, which is operatively coupled to a gas rod. A force is transferred via the gas piston and the gas rod to a lock of the locking mechanism. In operation, the gas rod transfers the force to a breechblock carrier of the firearm such as, for example, the breechblock carrier of the G 36 assault rifle. In some known examples, the gas piston, the gas rod and the breechblock carrier are individual components. However, in other known examples, the gas piston, the gas rod and the breechblock carrier are operatively coupled together. Gas pressure loaders may be classified into long stroke systems and short stroke systems. During loading of a firearm provided with a long stroke system, the gas piston moves approximately the same distance as the breechblock carrier. In contrast, during loading of a firearm provided with a short stroke system, the gas piston moves a relatively less distance than the breechblock carrier.
In other gas pressure loading systems, instead of directing the gas propellant toward a gas piston, the gas propellant is directed through the gas discharge to a gas pipe. In these gas pressure loading systems, the gas propellant is directed to the interior of the firearm. Specifically, the gas pipe directs the gas propellant to the lock of the locking mechanism. In operation, a force of the gas propellant impacts the breechblock carrier to facilitate reloading of known firearms such as, for example, the M16 rifle or the M4 carbine.
The overall weight of firearms that are not provided with a gas piston and gas rod is considerably less than the weight of a firearm provided with a gas piston and a gas rod. However, directing the gas propellant in the interior of the firearm often results in residue build up (e.g., residual gas or powder residue) that may cause the firearm to malfunction unless the firearm is frequently cleaned. As a result, the reliability of the M16 rifle was achieved only after significant development and improvement of propellants used with cartridges.
In contrast to firearms provided with gas pressure loading systems, most recoil-operated firearms have a non-secured locking system. In non-secured locking systems, the recoil energy from firing a round is directly utilized to load and reload the firearm. Specifically, in firearms having an unsecured blowback system or a semi-rigid roller lock, the recoil energy impacts a front side of the breechblock, which moves the breechblock toward the rear of the firearm to enable the empty cartridge casing to be ejected from the firearm and for the firearm to be reloaded. Some firearms that are provided with a non-secured locking system are the HK G3 automatic rifle, the Israeli Uzi submachine gun or the MP40 submachine gun of the German Armed Forces.
Known firearms, including firearms provided with gas pressure loading systems, recoil-operated firearms and/or manual repeating systems, are substantially inoperable and/or unreliable after they have been submerged and/or partially submerged in fluid. This may occur during training and/or operations in which the firearm is submerged in a body of water (e.g., a river, a lake, an ocean, etc.) and/or if the firearm is immersed and/or left standing in a fluid. Generally, the fluid (e.g., water) penetrates the interior of the firearm and particularly the firearm's locking system. Specifically, the gas pipe of firearms having a gas pressure loading system (e.g., firearms without a gas piston), such as the M16 rifle or the M4 carbine, fill with fluid, which then typically mandates the firearm to be disassembled and cleaned to restore operability and reliability.
In operation, if fluid penetrates the interior of the firearm such as, the locking system, the fluid may prevent a cartridge from being fired. Specifically, the fluid may decelerate movable components of the firearm utilized during firing such as, for example, a firing pin, to such an extent that the impact of the firing pin on a firing cap is insufficient to fire the round. Problems associated with fluid penetrating the interior of firearms has been generally discussed in U.S. Pat. No. 4,100,855, U.S. Pat. No. 3,300,888, and U.S. Pat. No. 3,553,876.